Practical Considerations for the Measurement of Internal and Coupling LossFactors on Complex Structures

摘要

A solution to the difficulty in calibrating true subsystem energies fromvibration measurements in statistical energy analysis is proposed. From measurements made on fully assembled structures, the following conclusions are obtained: internal loss factors can be directly calculated from subsystem energy injected power measurements without making any assumptions about the way in which power flows between subsystems; the accuracy of the calculated coupling loss factors can be considerably enhanced by using the fact that unconnected subsystems have zero coupling loss factors; for systems having three or more subsystems, there is a redundancy of information obtained via the consistency relationships and the resulting equalities, which involve triple products of coupling loss factors, allow an independent check on calculated values. It is suggested that an electrical analogy exists for vibrational power flow between subsystems.